Spectroscopic, structural and magnetic studies of nickel(II) complexes with tetra- and pentadentate ligands

Abstract

Two new nickel(II) complexes, namely [Ni-(BPSE)](BF 4 ) 1, and [Ni (5-BST)CH 3 OH]ClO 4 2 [BPSE = 2-benzoylpyridinesalicylidene ethylenediamine, 5-BST = 5-bromosalicylidene-tris(2-aminoethyl)amine] have been synthesized and characterized using various physicochemical methods. The magnetic and spectroscopic data indicate a distorted square planar geometry for complex 1, while complex 2 is assigned a distorted octahedral geometry. Complex 1 crystallized in the triclinic space group P-1. Complex 2 adopts an octahedral geometry with space group symmetry P 21/n. The superoxide dismutase activity of these complexes has been measured.

Design and reactivity of Ni-complexes using pentadentate neutral-polypyridyl ligands: Possible mimics of NiSOD

“…lie within the range expected for Ni(II) in an octahedral environment, and agree with results reported previously on similar Ni(II) complexes. 53,54 …”

New insight into the structural, electrochemical and biological aspects of macroacyclic Cu(II) complexes derived from S-substituted dithiocarbazate schiff bases

“…NMR, ESI, elemental analysis and single crystal X-ray diffraction confirmed cyclization to the pyrrole derivative. We postulate that bis(dithiocarbazate) indeed formed but subsequently hydrolyzed to mono(dithiocarbazate) and S-benzyldithiocarbazate [36,37] with subsequent cyclization of the mono(dithiocarbazate) to a pyrrole via the Paal-Knorr reaction. To our knowledge, this is the first pyrrole reported to be derived from a dithiocarbazate although there are two recent reports of formation of pyrrole byproducts upon reaction of thiosemicarbazone with 2,5-hexandione [38,39].…”

Synthesis, spectroscopic, electrochemical, magnetic properties and super oxide dismutase activity of nickel (II) complexes with unsymmetrical Schiff base ligands

“…These SODs disproportionate that toxic O 2 radical to molecular oxygen and hydrogen peroxide [14]. In a previous paper [15][16][17][18], we have reported mixed-ligand Metal (II) complexes with tris (2-aminoethylamine), triethylenetetramine, 1, 10-phenanthroline, 2, 2'-bipyridine, ethylenediamine. This paper describes the synthesis, spectroscopic, electrochemical, magnetic properties and SOD activity of nickel (II) complexes namely…”